I thought that most of the juglone problems arose from foliage, stems and husks, not roots. Will the predominant wind blow debris toward your garden?

I'd say that a 10' tree 40' distant means no problems for a long time.

Also for the long haul, keep a sharp eye as the tree rats will help them spread!

hortster

Don't know much about juglone and how its spread but could certainly research a bit more. Its fairly open around here so don't think there will be much issue with leaf debris until my garden really fills in. At that point winds from the east/southeast would be needed to get them in my yard. Can't recall what the predominant fall winds are.

I'm thinking there won't be an issue for long time either. Being inside during this cold winter keeps me thinking, lol.

"Being inside during this cold winter keeps me thinking, lol. "

Ain't that the truth!

Hope the kids are better today =)

Hey Jon, as a matter of fact they are! Thanks for the comment.

My 4 month old had a double ear infection and had three rounds of anitbiotics. The third type worked, which was a relief.

In reality, predominant wind directions are of little meaning in such situations. All it takes is one good day of S.E. wind, not weeks and weeks of it, to propel such material hither and yon. But very basically, one in the N. hemisphere can expect SE winds to occur ahead of cold fronts and low pressure systems, on the "front side", so to speak. Air tries to rush into a low pressure center but because of the earth's spin, it ends up circling around in a vortex. One can literally follow a storm system's progress and location simply by noting wind direction and changes in same.

+oM

The roots of a black walnut contain juglone just like the other parts of the tree. In fact, the concentration is higher in the roots than it is in the leaves. Both live and dead roots exude juglone. When other plant roots grow near black walnut tree roots, they can be affected by juglone in the soil near the black walnut roots.

Black walnut makes a big tree and the roots should be expected to extend well beyond the branches, same as with other kinds of trees.

Brandon7 is correct on this one. Black Walnut roots are the most serious source of juglone which suppresses growth of tomatoes, potatoes, and many other garden veggies. The rule of thumb is that the roots spread twice as far from the trunk as the tree is tall.

http://ohioline.osu.edu/hyg-fact/1000/1148.html

Picea pungens, Picea omorika, Pinus Cembra, Abies koreana and Cornus alternifolia are the main speces closest to the lot line.

Thanks for the link, OSU states the toxic zone is between 50 and 80'.

Not liking my odds here as three of the plants listed above are screening plants. May need to do a bit of research to see how these plants do with black walnut.

The Abies is the only one I'd worry about if I was planting a new tree in the root zone of the walnut. Since your tree will be well established by the time any roots get there you shouldn't have an issue. I put young P. cembra and Picea omorika (among others) in the root zone of a well established BW without any problems.

tj